He occasionally paints with a knife, but mostly with flat brushes to achieve "a kind of blocky modeling".

You need a nice, flat, firm brush.

To spread paint vertically with a flat brush, begin with an upstroke.

This ink is put on with a flat brush.

Dozens of paddle styles, thermal flat brushes, cushion handles and round vented models, gone.

Some manufacturers offer flat sable brushes two or four inches wide.

When painting vertically using a flat brush, begin with an upstroke.

To cut in properly, use a flat brush two or three inches wide.

The flat brush, slightly angled and going into your darker purple here.

Sable and nylon mix one inch flat brush by Osborne & Butler, Series 961.